There has been a trend toward wide use of various electronic components for high-temperature environment applications such as automobiles. Research and development have been performed actively on thermal characteristics of a resin substrate used for the electronic components, accordingly.
In a manufacturing process of the resin substrate, a resin composition is shaped into a sheet shape, following which the sheet-shaped resin composition (a resin sheet) is subjected to a curing reaction. This results in manufacturing of the resin substrate that includes a cured reactant (a resin cured product) of the resin composition.
Various proposals have been already made on, for example, a composition of the resin composition. Specifically, an epoxy resin having a mesogenic group has been used as a monomer in order to obtain a superior heat-conducting property (for example, see Patent Literature 1).